Lightning arrester



Aug. 28, 1928. 1,682,476

E. w. BREISCH ET AL LIGHTNING ARRESTER Filed April 18. 1922 WITNESSES: v INVENTORS Eq'yar WBre/sch 8: W Frama hm,

materials that they will function efficiently.

Patented Aug. 28, 192 8.

UNITED STATES EDGAR W. BREISCH, OF EDGEWOOD, -AND FRANK B. FALKNOR OF WILKINSBURG,

1,682,476 PATENT OFFICE.

PENNSYLVANIA, ASSIGNORS T0- WESTINGHOU$E ELECTRIC & MANUFACTURING COMPANY, A GOBPORATIQN OF PENNSYLVANIA.

LIGHTNING ABRESTER.

Application filed a t-n is,

()ur invention relates to lightning arresters, more especially to lightning arresters of the spark-gap type embodying spherical or hemispherical electrodes mounted on horn-gap which are commonly employed in power-transmission circuits.

It is among the objects of our invention to rovide lightning arresters of the abovedesignated type in which the electrodes shall be of a special design and composed of such over a wide range of atmospheric and weather conditions.

It is another object of our invention to provide an arrangement of spark-gap lightning arresters that shall function to break trical-transmission circuits and they have down at more uniform voltages than was hitherto the case.

Sphere-gap lightning arresters are well known for use as protective means for elecbeen employed in various forms and sizes, such as spheres and hemispheres of both large and small diameters used in conjunction with horns for diverting and rupturing arcs formed between the spherical surfaces.

It has been found that such sphere gaps are inefficientwhen subjected to rain or damp atmospheric conditions due to globules of water forming on the sphere surfaces either by condensation or direct contact with rain or other precipitation. This inefficiency is caused by the gap functioning as a olnt gap instead of a sphere gap as the spar has a tendency to arc across the points formed by the globules on the comparatively smooth surfaces of the spheres.

In our present invention, we propose to provide spherical spark gaps having porous surfaces designed to prevent the formation of globules by absorbing and distributing the moisture thereon.

.In the accompanying drawing, constituting a part hereof and in which like reference characters designate like parts,

' Figure 1 is a diagrammatic view of a sphere-gap lightning arrester representing one embodiment of our invention; and

Fig. 2 is a diagrammatic View of a modified form of lightning arrester.

Referring to Fig. 1, the numerals l and 2 represent a pair of substantially hemispherical electrodes having metallic horns 3 projecting therefrom, the electrodes being consilver, or other conductive material electrolytically deposited in the pores of the strucaure.

Instead of. these compounds, the electrode may consist entirely of porous spheres or hemispheres of carbon or any suitable conducting material having outer surfaces of relatively high porosity.

In the. Fig. 2 is shown a pair of spheres 7 and 8 mounted between a pair of hemispherical electrodes 1 and 2 to further guard against breakdown of the air gaps 6 due to point gaps caused by the formation of pro ecting globules of water. The object of the plurality of spheres and hemispheres is to provide a greater number of gaps 6 which operate on the assumption that globules of water will not collect on all the surfaces at average discharge capacity.

The device illustrated in Fig. 1 functions briefly as follows. When the voltage on the. line 4 becomes abnormal, owing to a sudden surge, such as is caused by lightning. a discharge will flow across the gap 6. Itwas found by experiment-that, if the electrodes .1 and 2 of porous composition are wet, the discharge capacity of the gap is approximately 90% of its normal dry rating, whereas when metal electrodes are employed, the difference between the discharge capacity of the Wet and dry surfaces is very great. This is due to the absorbent character of the porous material which either absorbs the moisture forming on the slightly roughened surface, or, as in the event of a short rain, the water is so distributed over the surface as to prevent the accumulation of globules. The device shown in Fig. 2 functions in a similar manner. I 7

It will be readily understood from the above description of. our invention that w of such a device under adverse embodiments of our invention, various modi- .a suitable conducting ca acity.

fications may be made in. the details of con.-

struction thereof. For instance, the sphere.

and hemisphere structures may be formed of any suitable material thatprovides porous working surfaces and body ortions of he use of the po rous bodies is not imited to the structures shown but the same may be employed in any electrical circuit where it is esired to (provide a gap between a pair of eleces. The bodies need not be s herical since other forms of electrodes may e used.

.These and other changes may be made in the details of construction of our invention without departing from the principles herein set forth.

We claim as our invention:

1. An outdoor lightning arrester adapted to be substantially unaffected by exposure to the weather andcornprising plurality of exposed spherical electrodes 0 porous porcelain compounded with carbonaceous material.

2. An outdoor lightning arrester adapted to be substantially unaii'ected by exposure to the weather an comprising two spaced rounded spark-ga electrodes exposed to moisture from bad weather, at least one of said electrodes being of a material which is conductive when dry and which is capable of preventing the formation of globules of water on the surface thereof when wet.

3. .An outdoor lightning arrester adapted to be substantially unaffected by exposure to the weather and comprising two spaced rounded spark-gap electrodes exposed to moisture from bad weather, at least one of said electrodes being of a material which is conductive when dry and which is sufficiently porous to absorb and distribute any moisture which is precipitated on the surface thereof.

4. An outdoor lightning arrester adapted to be substantially unaffected by exposure to the weather and comprising two spaced rounded spark-gap electrodes exposed to moisture from bad weather, at least one of said electrodes being of a porous insulating binding material having granulated conducting material distributed therein, said granulated material being conductive even when it is quite dr In testimony wiereof, we have hereunto subscribed our names this 13th day of April,

EDGAR W. BREISCH. FRANK B. FALKNOR. 

